JPH02274726A - Copolyester and its production - Google Patents

Abstract

PURPOSE:To obtain a copolyester improved in pigment dispersion and adhesion to a polyester film by polycondensing a specified acid component with a glycol component in the presence of a catalyst comprising a Zn compound and an Sb compound and/or a Ge compound and/or a Ti compound. CONSTITUTION:An acid component (A) comprising at least 60mol% aromatic dicarboxylic acid containing 0.2 to 10mol% sulfuric acid (alkali metal salt) (e.g. sodium 5-sulfoisophthalate) and at most 40mol% aliphatic dicarboxylic acid is mixed with a glycol component (B) comprising at most 40mol% ethylene glycol, 40 to 80mol% neopentyl glycol and at most 30mol% polyethylene glycol of an average MW of 100 to 6000 in a molar ratio of 1:(0.5-1.4). The obtained mixture is esterified at 230 to 270 deg.C, and the product is polycondensed in the presence of a polymerization catalyst comprising 0.01 to 0.1wt.%, based on the polymer, Zn compound and at most 0.2wt.% Sb compound, Ge compound and/or Ti compound to obtain a copolyester of an intrinsic viscosity of 0.3 to 0.8.

Description

DETAILED DESCRIPTION OF THE INVENTION [Industrial Application Field] The present invention relates to a polyester base resin for ink having good pigment dispersibility, good adhesion to polyester films, and good blocking resistance.

[Problems to be solved by conventional technology and invention]

Polyester film Biaxially oriented polyester film, particularly polyethylene terephthalate, has excellent electrical, mechanical, and thermal properties, as well as processability and chemical resistance, so it is used in magnetic tapes, capacitors, and packaging materials. It is used as a base film in a wide range of fields such as , photolithography, and electrical insulation materials. However, even with such excellent properties, the printability of polyester films varies depending on the condition of the film surface, and those with highly smooth surfaces have very poor ink adhesion. Conventionally, it has been known that adhesion can be improved by using a polyester copolymer with a low Tg as a binder for ink for polyester films with high surface smoothness. However, it tends to cause blocking on the printing surface, so it is not used as a standalone base resin, and the blocking resistance is improved by blending appropriate amounts of high Tg polyester copolymers, salt-vinyl acetate resins, and cellulose resins. However, on the contrary, adhesion and pigment dispersibility deteriorate, resulting in a decrease in the gloss of the coated surface. An object of the present invention is to provide a polyester base resin that has excellent pigment dispersibility, anti-blocking properties, and adhesion, which have not been achieved with conventional polyester binders.

[Means to solve the problem]

In the present invention, the aromatic dicarboxylic acid component is 60 mol% or more in the acid component, and the aromatic dicarboxylic acid component is 5 yen, 0.2
~10 mol% has sulfonic acid or an alkali metal salt of sulfonic acid in the molecule, the aliphatic dicarboxylic acid component is 40 mol% or less, and the glycol component has 40 mol% or less of ethylene glycol and 40 mol% or less of neopentyl glycol. 40～
It is a copolymerized polyester characterized by containing 80 mol % of polyethylene glycol having an average molecular weight of 100 to 6,000 and 30 mol % or less, and having an intrinsic viscosity of 0.3 to 0.8.

The polyester of the present invention comprises 60 mol% or more of aromatic dicarboxylic acid (containing 0.2 to 10 mol% of aromatic dicarboxylic acid having sulfonic acid or an alkali metal salt of sulfonic acid in the molecule) and 40 mol% of aliphatic dicarboxylic acid. % or less, a glycol (component) consisting of 40 mol% or less of ethylene glycol, 40 to 80 mol% of neopentyl glycol, and 60 mol% or less of polyethylene glycol with an average molecular weight of 100 to 6000, and esterification. Through a reaction, a zinc compound is used as a polymerization catalyst in a total of 0.01% by weight of the finished polymer, and at least one selected from antimony compounds, gelatinium compounds, and titanium compounds is used in a total of 0.2% by weight or less. Obtained by condensation.

The amount of aromatic dicarboxylic acid in the acid component of the copolymerized polyester of the present invention is 60 mol% or more, and the amount of aliphatic dicarboxylic acid is 40 mol% or less.

When the amount of aliphatic dicarboxylic acid is 40 mol% or more,
The Tg of the polyester is greatly reduced, resulting in poor blocking properties. As the aromatic dicarboxylic acid, terephthalic acid, isophthalic acid, phthalic acid, naphthalene-2,6-dicarboxylic acid, naphthalene-2,7-dicarboxylic acid, diphenyl-4,4'dicarboxylic acid, and diphenoxyethanedicarboxylic acid are used. . As the aliphatic dicarboxylic acid, succinic acid, oxalic acid, adipic acid, azelaic acid, sebacic acid, dodecanedicarboxylic acid, etc. are used.

0.2 to 10 mol % of the aromatic dicarboxylic acid component of the present invention has sulfonic acid or an alkali metal salt of sulfonic acid in the molecule. The amount of aromatic dicarboxylic acid having sulfonic acid or an alkali metal salt of sulfonic acid in the molecule is 0,
If it is less than 2 mol%, the dispersibility of the pigment in the resulting polyester will decrease, and if it is more than 10 mol%, foaming will be severe during production.
Moreover, the water resistance of polyester is reduced. Furthermore, if a sulfonic acid or an alkali metal salt of a sulfonic acid is not directly bonded to a dicarboxylic acid, the stability of the resulting polyester to solvents will decrease. Examples of aromatic dicarboxylic acids having sulfonic acid or an alkali metal salt of sulfonic acid in the molecule include sodium 5-sulfoisophthalate, sodium 3-sulfonaphthalene-2,6-dicarboxylate, and 3-sulfonaphthalene-2,7. -Dicarboxylic acids and the like are used.

The concentration of each glycol in the glycol component of the copolymerized polyester of the present invention is 40 mol% or less for ethylene glycol, 40 to 80 mol% for neopentyl glycol, and 6 to 6 mol% for polyethylene glycol with an average molecular weight of 100 to 6,000.
It is 0 mol% or less. 40 mol% ethylene glycol
As mentioned above, when the neopentyl glycol content is 40 mol% or less, the solvent solubility of the copolyester decreases. The average molecular weight of polyethylene glycol is less than 100 or 60
If it is larger than 00, the polymerizability will be poor and copolymerization will not be possible. Moreover, when the concentration of polyethylene glycol is 30 mol % or more, the polymer has poor polymerizability and is likely to cause blocking.

The intrinsic viscosity of the copolymerized polyester of the present invention is 0°3 to 0.
It is 8. If the intrinsic viscosity is less than 0.6, the viscosity when the copolymerized polyester is dissolved in a solvent will be low, resulting in poor workability and difficulty in removing the solvent, while if it is greater than 0.8, the viscosity will be high. It is not possible to raise the solids concentration sufficiently.

The copolymerized polyester of the present invention can be produced, for example, by polycondensation using a direct polymerization method. Polycondensation of the copolymerized polyester is also possible using the transesterification method, but in this case, it is preferable to lower the molar ratio of the acid component and the glycol component in the charge because the reaction rate during the transesterification reaction will be slow. In addition, since the copolymerized polyester of the present invention is a multicomponent system, when the transesterification method is used, increasing the molar ratio of the acid component to the glycol component at the time of charging will reduce the component composition ratio of the glycol component at the end of polycondensation. Since the ratio is significantly different from that at the time of preparation, a copolymerized polyester having a stable glycol component composition ratio cannot be obtained.The esterification reaction is performed at a molar ratio of acid component and glycol component of 1:1.05 to 1.05.
1.4, preferably 1:1.10 to 1.20. Within this range, the resulting slurry has good viscosity and stability. If the glycol component is less than 1.05, the esterification reaction may not proceed well, and if it is thicker than 1.4 degrees, the glycol component composition ratio of the finished polymer will be different from that at the time of preparation, so it is preferable. No. The esterification reaction is carried out at a temperature of 260 to 270°C.

In the case of a zinc compound, the amount of the catalyst used in the polycondensation of the copolymerized polyester of the present invention is 0.00% relative to the finished polymer.
01 to 0.1% by weight, and in the case of at least one selected from antimony compounds, germanium compounds, and titanium compounds, the total amount is 0.2% by weight or less. Examples of zinc compounds that can be used include zinc acetate trihydrate, basic zinc carbonate, zinc lactate trihydrate, zinc oxide, zinc chloride, zinc sulfate, and zinc salicylate trihydrate. Added amount of zinc compound is 0
．． If the amount is less than 0.1% by weight, the polycondensation reaction will progress very slowly (or not at all), and if it is more than 0.1% by weight, the polymer will be heavily colored. As a polycondensation catalyst, at least one selected from antimony compounds, germanium compounds, and titanium compounds is used in a total amount of 0.2% by weight or less. Examples of antimony compounds, germanium compounds, and titanium compounds include antimony trioxide, antimony chloride, germanium dioxide, Germanium chloride, tetramethyl titanate, tetraethyl titanate, tetrabutyl titanate,
Potassium titanyl oxalate, ammonium titanate oxalate, etc. are used. These catalysts can be added at any time before starting the polycondensation reaction. The polycondensation reaction temperature is in the range of 245 to 280°C; if it is less than 245°C, the reaction rate is very slow and the polycondensation reaction cannot actually be carried out, and if it is higher than 280°C, the decomposition rate of the polymer increases. Undesirable.

〔Effect of the invention〕

When the copolymerized polyester of the present invention is used, an ink binder with good pigment dispersibility and a good balance between adhesion and blocking resistance can be obtained.

The present invention will be specifically explained below with reference to Examples.

10- Example 1 Terephthalic acid 2923. ! 9. 405 g of sebacic acid, 118 g of dimethyl sodium sulfoisophthalate, 410 g of ethylene glycol, 137 g of neopentyl glycol
4,91 PEG-400880g and zinc acetate 0.6
3.9 was placed in a reactor, a pressure of 3 kg/cm2 was applied with nitrogen, and an esterification reaction was carried out for 1 hour while distilling water at an internal temperature of 230 to 265°C. After confirming that the esterification reaction product is transparent, add antimony trioxide 1
．． 32 g was added, and the internal temperature was adjusted to 275°C. Finally, excess glycol components were distilled off under a vacuum of 1 mmHg or less, and polycondensation was performed for 2.5 hours. The intrinsic viscosity of the obtained copolymer was 0.67. In addition, when the polymer was decomposed with an alkaline aqueous solution and the copolymerized components were analyzed using high performance liquid chromatography and gas chromatography, it was found that terephthalic acid/sebacic acid/sulfoisophthalic acid/ethylene glycol/neopentyl glycol/P
The molar ratio of E()-400 is 88/10/2/28/61
/11.

The obtained copolymerized polyester was dissolved in a mixed solvent of 60% toluene and 40% 2-butanone to obtain a solution with a solid content concentration of 40%. An ink was prepared using 60 parts of this solution and 40 parts of titanium oxide (manufactured by Ishihara Sangyo Co., Ltd.: R550). This ink was applied onto a 250 μm polyester film (Toshi T type) to a film thickness of 4 μm, and then dried at 50° C. for 3 hours.

(Pigment dispersibility) Gloss measurement of the coated surface of this film (60
°G) was performed.

(Adhesion) This film was scratched with a razor in the form of base lines with one line interval, and a peel test was performed using cellophane tape.

(Blocking Resistance) As a test for blocking property, cotton was placed on the coated surface, a load of 100 g was applied, and the condition of the coated surface was visually judged after 12 hours. The criteria for this evaluation were as follows.

5 → 3 → 1 There is no trace of cotton There is trace of cotton Cotton is effective These results are summarized in the second
Shown in the table.

Examples 2 to 4 and Comparative Examples 1 to 4 The same operation as in Example 1 was performed except that the raw material composition ratio of the copolymerized polyester was changed. The results are shown in Tables 1 and 2.

Table 1 The abbreviations in the table are as follows.

TPA: Terephthalic acid IPA: Isophthalic acid SA: Sebacic acid ADA: Adipic acid EG: Ethylene glycol NP (): Neopentyl glycol PE (): Polyethylene glycol (
Manufactured by Sanyo Chemical Industries, Ltd.) DMS: Sodium dimethylsulfoisophthalic acid Table

Claims (1)

[Scope of Claims] 1. The aromatic dicarboxylic acid component is 60 mol% or more in the acid component, and 0.2 to 10 mol% of the aromatic dicarboxylic acid component is sulfonic acid or an alkali metal salt of sulfonic acid. The aliphatic dicarboxylic acid component is 40 mol% or less, and in the glycol component, ethylene glycol is 40 mol% or less and neopentyl glycol is 40 to 80 mol%.
, polyethylene glycol with an average molecular weight of 100 to 6,000 is 30 mol% or less, and its intrinsic viscosity is 0.3 to 6,000.
A copolymerized polyester characterized by having a molecular weight of 0.8. 2. When producing the copolymerized polyester according to the first claim, 0.01 to 0.1% by weight of a zinc compound is added as a polymerization catalyst to the finished polymer via an esterification reaction.
and a method for producing a copolymerized polyester, characterized in that polycondensation is carried out using at least one selected from antimony compounds, germanium compounds, and titanium compounds in a total amount of 0.2% by weight or less.